Question

我有一个名为ChartView的UserControl。我有一个ObservableCollection类型的属性。我在ChartView中实现了INotifyPropertyChanged。

ChartEntry的代码是：

public class ChartEntry
{
   public string Description { get; set; }
   public DateTime Date { get; set; }
   public double Amount { get; set; }
}

现在我想在另一个View中使用此Control，并通过DataBinding为ChartEntries设置ObservableCollection。如果我试着这样做：

<charts:ChartView ChartEntries="{Binding ChartEntriesSource}"/>

我在xaml窗口中收到一条消息，我无法绑定到非依赖项属性或非依赖项对象。

我尝试将ObservableCollection注册为DependencyProperty，但没有成功。我尝试使用WPF Tutorial

中的代码

我的Attached-Property代码是

 public static class ChartEntriesSource
    {
        public static readonly DependencyProperty ChartEntriesSourceProperty =
            DependencyProperty.Register("ChartEntriesSource",
                                                typeof(ChartEntry),
                                                typeof(ChartView),
                                                new FrameworkPropertyMetadata(OnChartEntriesChanged));

        private static void OnChartEntriesChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {

        }

        public static void SetChartEntriesSource(ChartView chartView, ChartEntry chartEntries)
        {
            chartView.SetValue(ChartEntriesSourceProperty, chartEntries);
        }

        public static ChartEntry GetChartEntriesSource(ChartView chartView)
        {
            return (ChartEntry)chartView.GetValue(ChartEntriesSourceProperty);
        }
    }

这也行不通。如何将我的属性注册为DependencyProperty？

Answer 1

您似乎在AttachedProperty和DependencyProperty之间感到有些困惑。忘记您的ChartEntriesSource课程......相反，将此DependencyProperty添加到您的ChartView控件中应该可以解决问题：

public static readonly DependencyProperty ChartEntriesProperty = DependencyProperty.
Register("ChartEntries", typeof(ObservableCollection<ChartEntry>), typeof(ChartView));

public ObservableCollection<ChartEntry> ChartEntries
{
    get { return (ObservableCollection<ChartEntry>)GetValue(ChartEntriesProperty); }
    set { SetValue(ChartEntriesProperty, value); }
}

Answer 2

这里你不需要AttachedProperty。在ChartView添加DependencyProperty之类的

    public static readonly DependencyProperty ChartEntriesProperty =
        DependencyProperty.Register("ChartEntries",
                                            typeof(ObservableCollection<ChartEntry>),
                                            typeof(ChartView),
                                            new FrameworkPropertyMetadata(OnChartEntriesChanged));

    private static void OnChartEntriesChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {

    }

现在您可以绑定ChartEntries属性：

 <charts:ChartView ChartEntries="{Binding PROPERTYOFYOURDATACONTEXT}"/>

将属性注册为DependencyProperty

2 个答案: